ClickHouse .NET Core driver

This is an implementation of .NET Core driver for ClickHouse in a form of ADO.NET DbProvider API. This driver supports all ADO.NET features (with some exclusions like transaction support).

Features

supports binary protocol
compression (send and recieve)
timezones
most clickhouse column types are supported (aggregating ones are under development)
full support for .net async ADO.NET API
no unsafe code
~~tested~~- used in production
c# named tuple and record support
Dapper support (example in #19)

Usage

Install from NuGet:

dotnet add package Octonica.ClickHouseClient

ConnectionString syntax: Host=<host>;Port=<port>;Database=<db>;Password=<pass>, e.g. "Host=127.0.0.1;Password=P@ssw0rd; Database=db additionally, if you want to build a connection string via code you can use ClickHouseConnectionStringBuilder.

Entry point for API is ADO .NET DbConnection Class: Octonica.ClickHouse.ClickHouseConnection.

Extended API

In order to provide non-ADO.NET complaint data manipulation functionality, proprietary ClickHouseColumnWriter API exists. Entry point for API is ClickHouseConnection.CreateColumnWriter() method.

Simple SELECT async verison

var sb = new ClickHouseConnectionStringBuilder();
sb.Host = "127.0.0.1";
using var conn = new ClickHouseConnection(sb);
await conn.OpenAsync();
var currentUser = await conn.CreateCommand("select currentUser()").ExecuteScalarAsync();

Insert data with parameters

var sb = new ClickHouseConnectionStringBuilder();
sb.Host = "127.0.0.1";
using var conn = new ClickHouseConnection(sb);
conn.Open();
using var cmd = conn.CreateCommand("INSERT INTO table_you_just_created SELECT {id}, {dt}");
cmd.Parameters.AddWithValue("id", Guid.NewGuid());
cmd.Parameters.AddWithValue("dt", DateTime.Now, System.Data.DbType.DateTime);
var _ = cmd.ExecuteNonQuery();

For more information see Parameters.

Bulk insert

using var conn = new ClickHouseConnection("Host=127.0.0.1");
conn.Open();
using var cmd = conn.CreateCommand("CREATE TABLE IF NOT EXISTS table_with_two_fields(id Int32, name String) engine Memory");
await cmd.ExecuteNonQueryAsync();

//generate values
List<int> ids = Enumerable.Range(1, 10_000).ToList();
List<string> names = ids.Select(i => $"Name #{i}").ToList();

//insert data
await using (var writer = await conn.CreateColumnWriterAsync("insert into table_with_two_fields(id, name) values", default))
{
	await writer.WriteTableAsync(new object[] { ids, names }, ids.Count, default);
}

Build requirements

In order to build the driver you need to have .NET SDK 5.0 or higher.

MaceWindu/ClickHouseClient